1. Field of the Invention
Applicant's invention relates to precast barrier systems and a method of construction. More specifically, the present invention relates to a precast retaining wall with precast concrete columns and panels, and a method of constructing such a wall on a foundation surface.
2. Description of the Prior Art
In recent years, many civil engineering construction projects have used concrete barriers in numerous different applications; such as a retaining wall or as a barrier to keep out intruding people, animals, vehicles, fire, wind, light, sound, heat and the like. For a concrete barrier to be selected for these different applications, the overall cost of the barrier must be lower when considering the manufacturing costs, manpower costs and construction, and the time required to construct the wall. The barrier must also be durable and maintenance free with the possibility of a wide variety of aesthetically pleasing surface finishing. Cast-in-place concrete has given way to the use of precast concrete barriers. Precast concrete barriers are preferred because they can be manufactured at a lower cost with a higher degree of uniformity not found in cast-in-place concrete barriers. The precast concrete barriers may also be erected in numerous configurations and are capable of self support without massive construction.
Another cost which must be considered in many municipal areas is the availability of costs of purchasing right-of-ways for the construction projects. Consideration of the right-of-way requirements is particularly important in highway construction near residential areas. If the roadway is constructed near the residences, then the noise from passing vehicles and the impact of the noise on nearby residences must be considered. Ideally, the highway would be built far enough away from the residences so that the noise would not bother the residents. However, due to a continued growth of urban sprawl and the need for more highways, many times there is just not enough land available. In these situations, sound abatement walls are constructed to minimize the noise reaching the residents. Unfortunately, many of the current barrier designs require more right-of-way land than that which is available.
The need to reduce right-of-way requirements and the need to reduce costs has created a need for an environmental barrier system in which the width of barrier construction is small and which may be straight, curved, angled, or which may follow a terrain of any contour. The straighter and narrower the barrier construction, the lower the overall construction costs since less land must be acquired.
Current column and panel barriers experience a variety of problems. One problem associated with column and panel barriers is the need to very precisely position adjacent columns if prefabricated panels are to be positioned in between. The positioning problem includes not only the column-to-column spacing but also the plumbness of the column, both to the wall face and the panel ridge. Once the panel dimensions arc selected, then the panels are fabricated, and the spacing between adjacent columns must correspond to the paneling for the full exposed length of the column. If precise column positioning is not maintained, then the panels will not fit between columns which are spaced too close, or the panels cannot be attached to columns which are spaced too far apart.
In typical precast concrete construction, tolerances of plus or minus one-quarter inch or more are common, depending upon the fabricators' experience and the cost of forms. Accumulation of such tolerances require that positioning and placement of columns be very precise in order to accommodate the precast panels there between. Precise tolerances on the lateral spacing between columns can be very difficult to maintain at construction sites. Consequently, accumulation of tolerances can lead to a loose joint between panels and columns. With a loose joint, vibration can occur and sounds and the like and other forces or energy can pass through the barrier. The present invention overcomes the problems with precise tolerances without any significant additional costs.
Another problem associated with column and panel barriers concerns thermally induced, linear expansion and contraction of the completed barrier. Thermal variations in the wall can lead to loose joints during contraction as discussed above, structural damage of columns and panels due to compressive stress developed during expansion, and construction difficulty when large thermal variations occur during construction. Thus, there is a need for a precast concrete barrier which overcomes problems of the type discussed above for column and panel barriers.